#include<stdio.h>
double f(double x,double a3,double a2,double a1,double a0);
int main(void)
{
	double a3,a2,a1,a0;
	double a,b;
	scanf("%lf %lf %lf %lf",&a3,&a2,&a1,&a0);
	scanf("%lf %lf",&a,&b);
	
	int isresult=0;
	do{
		if(b-a<0.001){
			isresult=1;
		}else //if(f(a,a3,a2,a1,a0)*f(b,a3,a2,a1,a0)<0){   不能加这句话，否则如果多项式的根刚好是区间的断点，则该程序会无限循环下去 
			if(f((a+b)/2,a3,a2,a1,a0)==0){
				isresult=1;
			}else if(f((a+b)/2,a3,a2,a1,a0)*f(a,a3,a2,a1,a0)>0){
				a=(a+b)/2;
			}else if(f((a+b)/2,a3,a2,a1,a0)*f(b,a3,a2,a1,a0)>0){
				b=(a+b)/2;
			}
	//	}
	}while(isresult==0);
	
	printf("%.2f\n",(a+b)/2);
	
//	printf("a3=%f",a3);
	return 0;
} 

double f(double x,double a3,double a2,double a1,double a0)
{
	double y;
	y=a3*x*x*x+a2*x*x+a1*x+a0;
	return y;
}